How many three-letter sequences are possible that use the letters q, u,a, k,e, s at most once each?

70

step-by-step explanation:

2*5=10

4*15=60

60+10=

70

the mistake in the pattern is that :

b. the decimal point was moved one too many place values each time

the correct pattern could be made by :

b. moving the decimal point to the right the same numbers of place values as the exponents